1. Field
One embodiment of the invention relates to an audio-visual (AV) apparatus operated by a remote controller using wireless transmission, and to improvement of its control method.
2. Description of the Related Art
As already known, various audio-visual (AV) apparatuses have come into wide use. An optical disk reproduction apparatus reproducing an optical disk such as a digital versatile disk (DVD) is given as one example of an AV apparatus. In the foregoing AV apparatus, the user wireless-transmits operation information using a remote controller, and thereby, the apparatus is remote-controlled to various operation states and a stop state.
In this case, for general home AV apparatuses, the following two means for wireless-transmitting operation information to the AV apparatus from a remote controller are used. One employs an infrared method of transmitting the operation information using infrared rays as a transmission medium. The other employs a radio wave method of transmitting the operation information using a radio wave as a transmission medium.
Of the foregoing methods, according to the infrared method, a remote controller must be pointed toward the AV apparatus to transmit operation information in a state that there exists no obstacle that shields infrared rays on the straight line connecting the remote controller and the AV apparatus.
Conversely, the radio wave method is a method used for performing bidirectional communication between the remote controller and the AV apparatus. Thus, even if an obstacle exists on the straight line connecting the remote controller and the AV apparatus, the operation information is transmitted to the AV apparatus, and further, it is transmitted from the AV apparatus to the remote controller.
Currently, an audio-visual (AV) apparatus that is operable using a remote controller employing both the infrared method and radio wave method, is available. This kind of remote controller operates in the following three modes. One is an infrared only mode of transmitting operation information using only infrared rays. Another is a radio wave only mode of transmitting the operation information using only a radio wave. Another is a combination mode of simultaneously transmitting information using both infrared and a radio wave. The foregoing modes are settable by the user.
An AV apparatus receiving the operation information from such a remote controller has the following functions. One is a function of receiving the operation information transmitted using infrared rays. The other is a function of receiving the operation information transmitted using a radio wave. The foregoing AV apparatus can handle the operation information received using either of the foregoing functions.
As described above, the AV apparatus is remote-controlled using the remote controller having both the infrared method and the radio wave (frequency) method. This serves to obtain the advantages of the foregoing two methods. However, according to the combination mode, the remote controller simultaneously transmits the same content operation information using infrared rays and a radio frequency. For this reason, power consumption is greatly increased; as a result, this is a factor of shortening the lifetime of a battery.
Jpn. Pat. Appln. KOKAI Publication No. 2008-28582 discloses the following technique. According to the technique, the power supply to a radio transmit/receive module is stopped in a standby state, and power is supplied to an infrared transmit/receive module only. In this way, power consumption of a recorder is reduced. Further, when an operation instruction signal for changing the recorder from the standby state to a normal operation state, the recorder transmits a radio response signal to the remote controller to stop the transmission of the operation instruction signal. In the manner as described above, the power consumption of the remote controller is reduced.